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What is LASI

LASI (LAyout System for Individuals) is a relatively simple "general purpose" layout and design system originally intended for integrated circuits. It is versatile enough that it can be used for ICs, MEMS and other nanotechnolgies, discrete devices, schematics, PC boards and project documentation drawings. LASI is intended for both educational and professional use.

A very simple version of LASI was written for MS-DOS in the mid-80's. When Windows came out, LASI was rewritten as version 6 for Windows. The current version 7 is more elegant, functional and is intended to run on Windows versions XP, Vista or Windows 7.

For students LASI teaches a better understanding of what you are really doing. To use LASI, you need to know something about your technology, the physics involved and have some circuit intuition, not just know how to run software. It is for people who still consider IC design something of an art.

The original intention of LASI was to aid commercial design systems. It still has that purpose since layout work can be done on any Windows PC or Laptop, Linux systems using Wine, and then be transferred using common formats such as GDS.

LASI also runs portably. You can install the system on a flash drive or other removable drive and work on drawings also stored on that same drive. Portable operation lets you do work on any convenient PC without leaving any files on that PC. This is handy for presentations and for student projects.

Drawings are built from hierarchical cells stored as individual TLC (Transportable Layout Cell) files. TLC files can be easily traded between different drawings. TLC files are in a basic XML format.

LASI consists of a main drawing editor program and several "utility" programs. These utilities include GDS, CIF and DXF format converters, a user programmable bitmap based DRC, a basic matrix router, and a Spice netlist compiler that extracts Spice circuit files from both schematic and layout. The utilities can run independently or directly out of the editor.

LASI compiles Spice netlist files but does not do simulations. There are good Spice simulators available already. Spice simulations can be quite customized and are better not integrated into LASI. However most simulators can run directly out of the main editor or the Spice compile utility.

For anyone who is not familiar with LASI or its utilities there is a large built-in Help file system.

Although it is well developed software by now, LASI is still an ongoing project. There is always something that you can add, improve or fix. Watch this site for the latest version. Updates are approximately every couple of months, longer if few changes, sooner if necessary.

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What's New

7.0.76

• Memory allocations have been increased for the Spice compiler utility LasiCkt for more virtual nodes. This lets the utility add a large number of internal connection nodes to the Spice file to find possible layout errors.

• LasiCkt can now compile just Connector Text script files and skip the Spice circuit file. The script can then be used to add connectors to a cell and reduce Spice compile time.

• The the design rule checker LasiDrc and LasiCkt now continuously show the running time. This gives you an indication that the program is running and how long it might take. Both programs can take a long time to run.

• Most utility program windows can now be minimized and will pop up when finished. In general, if you are careful, long running programs can be minimized to the Windows task bar and can then run other programs.

• Control panel buttons on utility programs now lock out when a program is running. This prevents multiple instances of the same program or changing setups while a program is running. To stop and unlock a utility before it finishes you need to press ESC.

• Small changes and fixes have been made to the main editor and most of the utilities.

7.0.75

• The GDS conversion utilities Gds2Tlc and Tlc2Gds now write text files that translate the binary GDS records to plain text. These files should be educational and very useful as diagnostics by showing what is really written in a GDS file.

• The Spice compiler LasiCkt has been greatly revised to make it much easier to compile Spice circuit files from layout or schematic. It will run as previous versions, or as a two pass compiler. On the first pass, it writes script files that add Connector Text on real or virtual nodes. On a second pass, it reads the script, temporarily adds connectors to the cells and recompiles. Adding connectors lets you find certain layout errors that might be missed.

• The Spice compiler LasiCkt has also had some setup changes that eliminate some rarely used options. It also has some improved checks for cell layout errors that can cause incorrect or unworkable Spice circuit files.

• Most of the LASI Addon tutorials have been updated with revised LasiCkt sample compiles and connector scripts.

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